MKIV "high tech" yaw string (tech note)

I recently heard from an owner having installed a MKIV yaw string on a FES (front, electric, self-launch/sustainer) equipped glider. He said that the MKIV was not indicating straight back centered in level flight, being slightly off to the side and deflection in turns was "not even, more sensitive in one direction" (my words).

Since all MKIV yaw strings are carefully obedience trained and calibrated before leaving my shop (g), there had to be something affecting the flow over the canopy. I suspected the culprit might be the folded prop, given the ship's rigging apparently checked fine. I suggested installing temporary yaw strings further back on the canopy to determine how far aft the string would need to be located to behave in an acceptable manner - then mark that spot for the warranty* replacement. I think that worked and all is well (I hope).

If installing a MKIV on a FES equipped glider, please determine suitability of chosen location by test flying with temporary yarn/s prior to installing the MKIV.

MKIV's and Quiet Vents are available on-line at Craggy Aero, Cumulus, and Wings & Wheels!

*For warranty replacement - please contact me directly. IF you read the installation instructions and still goof, that's covered too (once!), warranty coverage is at my sole discretion (but I'm easy).

all the best,

bumper

bumperm at frontier dot
com